Fuel injection pump



Dec. 2, 1941. E M, ,PURDY Re. v21,966

FUEL iNJEcTION PUMP Original Filed Nov. 7, 1955 4 Sheets-Sheet 1 Dern 2,1941. E M, PURDY Re. 21,966

' FUEL INJECTION PUMP Original Filed Nov. '7, 1935 4 Sheets-Sheet 2 r J..EL 7a 52T :1

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TORNEY 2, 1941. E M, PURDY Re. 21,966

FUEL INJECTION PUMP Original Filed Nov. '7, 1935 4 Sheets-Sheet 5 6 Zw y63@ Zw S@ 22, 66a,

s f' K 2a' 20a i lm isn-l2. INVENTQR ,mamma/WMM@ Dec. 2, 1941. E. M.PURDY FUEL INJECTION PUMP 4 sheets-Sheet 4 Original Filed Nov. 7, 1935ee 60 U8 man, )www I Reissued Dec. 2, 1941 i UNITED STATE s PATENToEI-lcE EUELmJEcTIoN PUMP Everett M. Purdy, Brooklyn, Nl. Y., assignor`to Eisemann Mag-neto Corporation, New York, N. Y., a corporation of NewYork This invention relates to fuel injection pumps. for internalcombustion engines and more particularly internal combustion enginesfiring par-` tially or wholly by the heat of compression and it is anobject of this invention to provide an improved device of the typedescribed of simplel mechanical construction and small size which shallprovide for the control of the fuel t all cylinders of the engine by asingle adjustable l control valve equi-distant from all the pump\multaneously by rotating the pump casing on its mounting and in whichthe time at which the injection of fuel starts in each engine stroke isautomatically 'advanced or retarded as the amount of fuel injec isincreased or decreased respectively, and it is also an object of thisinvena further modication;

tion to provide a fuel injection pump `which may ce controlled by agovernor of` light and sensitive construction and which is flexible inits adaptation to various conditions of installation.

In the drawings- Fig. 1 is a top plan view of a fuel injection pumpconstructed in accordance with this invention; v

Fig. 2 is a view in rIside elevation of the fuel l injection pumpV shownin Fig. l, parts beingbroken away to show other parts more clearly;

Fig. 3 is a view in vertical section taken as on line 3-3 of Fig. l; V

Fig. 4 is a partial view in horizontal section taken as on line 4 4 ofFig. 3;

Fig. 5 is a fragmentary view in vertical section taken as on line 5-5 ofFig; 4 and showing one form of fuel control valve and its seat;

Fig. 6 is a fragmentary view in vertical section taken as on line 6-6 ofFig. 4 and showing a. fuel injection plunger and the bushing or casingin which it operates;

Fig. 7 is a partial'view in vertical section taken similarly to Fig. 3of ay fuel injection pump of modified construction:

Fig. 8 is a fragmentary view in horizontal section taken as on line 8-6of Fig. 7;

Fig. 9 is a fragmentary view in vertical section operating cam and camfollowerfor the fuel iny of the fuel control valvemshown in Fig. 7, thevalve I being raised from its position in Fig. 7;

Fig. 10 is a fragmentary view in vertical section taken `as on lineIll-Ill of Fig. 1I and showing an injection plunger and its casing ofmodified construction;

Fig. l11 is a fragmentary view in `horizontal section taken as on lineII-II of Fig. 10; Fig. 1 is a fragmentary view in vertical section ofthe structure shown in Fig. 10, taken as on line |2-I2of Fig. 13 so asto show other portions of the structure and with the injection plungerraised to its uppermost position;

Fig. 13 is a fragmentary view in horizontal Vsection taken as on lineiS-Ilof Fig. 12;

Figs'. 14 and 15 are partial views in' vertical section of furthermodifications; Fig. 16 is a fragmentary view in vertical sec tion of thecontrol valve shown in Fig. 15; Fig. 17 is a fragmentary view inhorizontal section taken as online i1l`| of Fig. 16;

Fig. 18 is a fragmentary'view in vertical section showing the upperportion. `.of a fuel iniection` plunger of Fig. 15;

Fig. 19 is a partial view in Fig. 20 is` a fragmentary view in verticalsection showing the fuel control valve of Fig. 19; Fig. 21 is afragmentary view in vertical section showing the upper portion of a fuelinjection plunger ofiFig. 19; p

Figs. 22 and 23 arepartial vertical sectional views showing furthermodications; and

Fig. 24 is a 'fragmentary view, partly in vertical section showing,detachedfrom the casing, an

jection plunger of` modified construction.

As shown in the drawings, referring pagicularly to Figures 1 to 6inclusive, a fuel injection pump constructed in accordance with this in`vention comprises a casing consisting of a sub. stantially cylindricalportion l'having a rectangular flange 2 at one end thereof by which itis secured to a correspondingly shaped flange I of a lsecond casingportion 4. The casing portion I ls also proI ded with an annular flangeI which fits within an opening i of the casing portion 4. Screws 'Ithreaded into openings in the flange 3 secure the casingV sectionstogether. 'Ihe casing section I lsprovided with a plurality of b'ores ortl placed with thelr'axesspaced uniformly in a vertical section ofcircle about the central axis of the cylindrical portion I of thecasing. The bores'. vary in diameter at different portions of theirlength and in each bore there is a tubular plunger follower 4I0 havingone end thereof closed and which is slidably mounted in that portion ofthe bore 0 adjacent the casing portion 4 and held against turning by apin I2 which engages in a slot I4 formed in the side wall of the plungerfollower; In each bore 0 there is also fitted a fuel plunger bushingvor' cylinder `I6 which extends into the follower I0 and is bf greaterdiameter at one end so as to engage with a shoulder Ifformed in the bore6. The bushing I has a cylindrical opening or bore of uniform ameterthroughout its length in which is slidably mounted the fuel plunger orpiston 20. The plunger 20 at one end extends beyond the bushing I6toengage the closed end of the follower I0 and its projecting end isprovided with a spring seat 22 held in position by a spring wire 24which engages in a groove 26 in the plunger. The spring seat 22 servesas avseat for a spring 28 which is confined between the spring seat anda shoulder formed in the bore 8 and'which holds the end ofthe plunger 20in engagement with the follower I0.

To operate the follower I0 and fuel plunger 20 `l the lower end of thefollower I0 is recessed to receive a roller 30 mounted on a pin 32 whichexchamber 60 the bore is of larger diameter andy.' has seated therein aplug 64 which is held in position by a screw threaded plugv 66. 'I'heplug 64 is provided with a plurality'of passages 6B arranged on thecircumference of a circle and/ communicating at one end with the chamber60 and at the other end with a chamber 10 formed between the plug 64 andthe plug 66. Centrally located in the plug 64 is a tapered -bore whichcommunicates at its upper end `with the lcham-l ber 'I0 and at its lowerend with the ports or passages 12 extending radially through theplug 64and the body portion of the casing I to comy municate with the bores ofthplunger bushings vthe tapered opening inthe plug 64.

I6 through grooves 14 formed in the bushing I6.

`In the tapered opening in the plug 64 is a. tapered' valve J5 having acylindrical stem which is slidably mounted in an opening in the plug 66.The valve I5 is provided at its outer end with a head 'I6 which forms aseat for a spring 13 confined between the head 16 and a shoulder on theplug 66. The spring 13 tends to raise the valve 'I5 in Ports or passages00 extendingradially from the chamber 60' communicate with grooves 82inthe bushings I6 and an axial port or passage 04 in each plunger tendsthrough a transverse opening in the fol-` lower I0 and is held inposition by a'sprin'g wire 34 engaged in notches in the pin 32 and agroove in the follower I0. The roller 30 is positioned to be engaged bya'cam 36 formed integral with a 20 extends from the end of the plunger20 toa transverse port or passage 06.

To control the fuel supplied to the engine cylinders by the pump thevalve 15 is controlled by a governor 0B which may be of the usual-balltype and which operates through lever 80 and links 92 to operate a lever94 pivotally mounted as at gear 38 on the end of a shaft 40 which ismounted in the casing portion 4 and arranged to be driven in suitablemanner from the engine with which the pump is associated. .The shaftyextends through a cylindrical boss 4'I formed integral with the casingportion 4-and which is rotatably mounted in a'bracket 4I suitablysupported from the engine. A set screw 4I,threaded into the l braclret4I and engaging in a groove 4b formed i ln the boss 4 secures the pumpcasing to the bracket` and permits of rotative adjustment of the casingwith respect to thebracket. To prol vide for the free operation of thegear 38 and cam 36 the gear wheel is supported by a thrust bearing 42and the shaft 40 is guided by a ball bearing 44, an oil seat 46 beingprovided'between the bearings 44vand the facuof the casing portion 4 inorder to prevent leakage pf the lubricant along the shaft 40.

4Threaded into the bore 0 at the free end of the casing section I is aplug 48 which retains the'plunger bushing I6 in its position in the boreI and which is provided with a. central opening f having a portionthereof shaped to provide a seat for the check valve 50. The plug -40above the valve A is bored to receive a coupling member l2 having acentral opening which communicates with a 'chamber above theefvalve 50and is en-x larged immediately above the valve 50 to receive a spring 64which returns the check valve 60 to its seat. A second coupling member56 cooperates v with the coupling member 62 'in securing the end of apipe 60 which connects the individual plunger y bore to a cylinder ofthe motor with which-the pump is associated.- Y

At the axis of the casing 'portion I .andequi- `distant from all of theplunger bores'is a bore `through which the gear 3B is accessible.

96 in a bracket 00 secured in the free end of the casing portion I. Thelever 04 has a bearing portion 99 which bears on the head 16 of thevalve 15 so that operation of the governor will cause movement of thevalve to restrict or enlarge the passage between the tapered valve '15and the wall ofthe tapered port in which it is mounted so as to vary thesupply of fuel therethrough. The

.governor 061s arra/nged so that as the speed 0fthe engine increases thelever 94 is operated to beardown upon the head 16 of the valve forcingthe valve 15 closer to its seat against the action ofspring 10 so as torestrict the ow of fuel to the bores in' which the pump plungers 20Voperate.

lThe governor Il is driven through a shaft |00 on which is xed a gear|02 which meshes with the gear-30, the shaft |00 and gear |02 beingmounted in a casing I04 having aseat which fits one of a plurality ofpads- |06 formed on thecasing portion 4,which pads surround openings Thepads |06 permit of the attachment to the casing portion 4 of variousaccessories used in connection with the injection pump such as the fueltransfer pump and the fuel filter.

In the construction just described rotation of the cam 36 bythe shaft 4lcauses the cam 26 to engage the rollers 30 in succession and operate thefollowers I0 and the plungers 20. shiftingeach follower I0 and Yplunger2l between the position shown at the left-hand side of Figure 3 and thepositionshown at the right-hand side of Figure 3. The rate atwhich theplungers are operated and the time during which they remain in thedifferent positions will be determined by the contour of the cam 26. Asshown, the cam 36 retains each plunger 2l in position to main- A tainvthe ports 12 closed as shown at the righthand side of Figure 3throughout the time in which all the 'otherplungers 20 are beingoperhaving yan inner portion forming a chamber I0 ywhich is incommunication through an opening l2 with a source of fuel supply-Abovejth ated, lowering eachplimger to the position shown at theleft-hand side of .Figure'S only when it is Y with fuel for the enginecylinder. With a plunger .20 rai-sed, as shown vat the right-hand sideof Figure 3, movement of the' cam 36 past its roller 3|) permits loweror retracted position by the spring 28 and a partial vacuum in beestablished abovethe plunger 20 so that upon the openingof the port I2by movement of the plunger'past the groove plunger 20 to be`moved to its5 Il fuel is drawn from the fuel chamber B through lo the ports 'sa inthe plug s4, chamber 1n, past valve'Ii and through vthe passages I2 intothe ychamber formed by the bore in bushing 'I6 vabove the plunger 28.Furthenmovement of the cam 36 causes the cam-to raise the follower I0and l5 the plunger causing the plunger y2|! to seal the' passage I2 andto place the fuel in the chamber above the plunger under pressure,forcing fuel past the check valve 58 and through the passage in the plug52 andthe pipe 58 to an engine 20 cylinder.

In order that the fuel may be delivered to the engine cylinders in pfinely atomized condition it is customary to place in the deliverynozzles spring-biasedrvalves which open only' at a high .25

pressure so that as the plunger 2li` forces the fuel past the checkvalve the vfuel is under a high ydegree of pressure. In order that thesupply of fuel to an engine cylindermay be cut of! sharply at the end ofthe injection stroke the ports or 30 passages 8l and 86 are provided inthe plunger 2D. Throughout the movement of the plunger .2li the end ofthe passage 88 is sealed bythe wall of the plunger bushing I6 until theplunger is theY fuel chamber 6|! thus releasing suddenly the raised toplace the passage 8B in communication 35 -give -a veryfne graduation asthe valvek cuts pressure above the plunger 128 and causing the 40 valvein the delivery nozzle to cut off the supply to the engine cylindersharply. Valve 58 seats immediately upon' the fall of thepressure abovethe plunger 2l) and prevents back flow of fuel from the pipe 58.

As the relative positions of the ports 86V and grooves 82 are determinedand fixed the point at which the fuel injection to` the cylinder is 'outoff l remains fixed. The point at whichthe fuel injection starts willvary to some extentv with the s..

amount of fuel supplied to the engine cylinders at each operation of thepump;` thus, when the e valve.15 is openedto a greater extent thechambers above the plungers 2B will receivelarger the fuel plungers l28are mounted and operated in the same manner as the plungers2|| of theFig. 3. Each plunger 20, however, is provided with agroove I|8 whichcommunicates through radially extending ports or passages 86a with alongitudinally extending port `8W. The casing portion I is provided withan axially positioned bore having therein'a plug formed of a lower orinner portion I|2 and a separate upper or ou er portion ||2. bothportions being held in pos' tion by a plug 66.. The lower portion ||2 ofthe plug has a central bore ||4 which communioates with the chamberGIVformed by the lower portion of the bore of the casing I and withangularly shaped grooves |`|6 formed in the upper face of the portion H2of the plug, the upper i portion H2* of the plug closing the upper edgesof the grooves s'o as to make closed triangularly bore which forms acontinuation ofthe bore III and mounted therein is Aa cylindrical valveIii which may be operated in the same manner as the valve 15 of theprevious modification. The ,lower or inner end of the valve 15EL is fiatso as to form a sharp cut-off for the triangular passages I|6. It willbe noted that the passages IIB have the narrowest portion thereof atthe. bottom and that the operation ofthe valve 15B is the same astheVoperation of the valve fliiy of the previous modification, that is,movement of the valve 15B in a downward direction cuts off the supply offuely to the chambers above the pump plungers 28, the tapering of theypassages ||6 serving to oil' but the valve 'I5'L controls the ports I|6individually instead of controlling a common port as does valve 15 ofthe previous modification. In this modication ports or passages 8|)ilestablish communication from ports in the plunger bushings ISI to a fuelchamber IIB which, as shown, is in communication through a port |20 withthe fuel supp1y,vbut the chamberi I8 may.v if desired, be extendeddownwardlyso as to connect with the chamber which is in'communicationthrough the port 62 with the fuel supply as in the previousmcdiflcation. In this modiflcatfon as a plunger 2|I is forced downwardlyquantities of fuel than when the valve I5 is more gh.,

nearly closed and with larger quantities of fuel in the chambers abovethe plungers the pressure on the fuel kis raised tothe point at whichdischarge. to .the engine cylinder starts upon' a fshorter movement ofthe plunger, thus the dis- @un charge starts earlier with a larger thanwith a' smaller quantity of fuel. Both the time of be-` ginning and thetime of ending the injection. of the fuel may be advanced or retardedsimulby its springI 28 fuel is drawnfrom the chamv ber 60 through the`passage III, past the valve Iiil and through a port I6 to the chamberabove the plunger 20'. i Movement of 'the plunger upwardly by the camforces the fuel past the check valve 5 0 tothe engine cylinder, ports8h. and 86- e being closed by the 'bushing wall, until the groove I IUin the plunger 72|I is connected to the passage 88'* whereupon. pressureabove the plunger 2i)a is vented through' the ports 84, 86,` groove I I0i and passage to the chamber. ||8 whence it taneously by rotating thecasing with respect to the 'bracket 4|. As the casing is Vrotated thecam 36, because of the connection by which it is driven from the engine,remains relatively fixed so that rotation of p the casing varies thetime relation of the operation of thepump plungers with re'- To i thedischarge vfrom the chamber above that spect to the operation of theengine pistons and makes 'the same adjustment simultaneously with`respect to the .pump plungers for all the engine cylinders.

will pass through the passage |20 to the fuel supply or, if theconnectionbe so mai-cle, to the chamber 610. Y 'i l In the modificationshown `in Figures 10, l1, 12 and 13,ithe-jgs'upply of fuel to thechamber above a pump plunger may be controlled by a valve, s'uchfaseither vof the valves 1 5, 15a, and

plungermaybe' either to a fuel supply chamber 60 or to a fuel chamberII8 as shown in the `lb'at a distance from the washer |22.

placed between the plug 48 and the bushing I6h closing the directpassage from the chamber above the pump plunger 20b to the check valve50. The pump plunger 20| is grooved as at |23 and 24 and from the groove|24 there extends a transverse port |26' which establishes communicationfrom the'groove |24 to the axial port or passage 84h. The bushing I6b isprovided with a port or passage |28 which connects a chamber |30 belowthe valve 50 with the central bore of the bushing at a distance from thevalve 50. The bushing |6b is also provided with a passage |32 whichcommunicates with a port |34 formed in the washer |22 so as to establishcommunicationY from the chamber above the plunger 20h to the centralbore of the bushing The In the modification shown in Figures 15, 16, 1'1and 18 the fuel supply valve 15d is shown lprovided 'with a threadedstemV engaging the plug 66d for manual adjustmentof the valve although,of course, this valve may be arranged for adjustmentby a governor as inFigure 2, if desired. The valve d is grooved as at |40 and its inner endportion |4| of full diameter is shaped to provide a at inclined surface|42 on onev side of the valve which cooperates with a s houlder in. thevalve chamber in controlling the passage of fuel through the port ||4 inthe plug |43. Controlling a port common to all the pump sections of thedevice prevents slight irregularities in the port sizes from affectingthe amount of Vfuel supplied to the engine cylinders. The pump vplungers 2||d of this modification are grooved plunger h when releasedby the cam and forced down by its spring 28 creates a partial vacuumabove the plunger 20b and upon the opening of the chamber above theplunger. Upon operation of the plunger by the cam to force the fuel tothe engine cylinder movement of the plunger first closes the passage 12and continued movementl thereafter forces the fuel ,above the plunger'20h through the passage 84| to the port |26 and groove |24. Groove |24establishes communication with the passage |28 as the passage 12 isclosed so that the fuel is-forced from the chamber above the plunger 20bthrough the ports 84,

passesto the chamber above the plunger`20b will rise above the fuelcausing fuel 4only to be forced through ports 04b and |28 to the enginecylinder.

. the port 12 by the plunger fuel is supplied to as at |42, |44, andhave an axial port 84d and transverse ports |46 and |48 communicatingwith the grooves |44 and |42, respectively. In this construction thechamber H8*i surrounding the plug |43 may be connected to the source offuel supply through the port |20cl and through ports 80d to the boresfor the pump plungers 20d. The ports |6d connect the bores for the pumpplungers to the bore orchamber in which the valve 15l is mounted. In theoperation of this device when ^a plunger 20d is retracted fuel issupplied through port I20d, chamber ||8d and port 8|)d to the pumpplunger bore at the groove |44,dthence through the transverse port |46and the axial port 84Li to the chamber above the pump plunger. The port|48 and the groove |42 of the pump-plunger are at this time closed bythe bushing, |6d andthe upper end portion of the plunger, which is offull diameter seals the port I6". rAs the plunger is raised the port8|)d is cut off and communication between the groove 44 of the plungerand the bore for the valve 15d is established through The vapor isvented through `ports |34 and |32 e to the supply.

In the modification shown in Figure 14 the position communication isestablished betweencontrol valve 15 is formed with an end of frusptro-conical shape and lcontrols a plurality of passages 8 leading td'thebores of the pump plungers. The passages ||6 are of triangular shape as"in- Figure 7 and the fuel is supplied thereto from the fuelsupplychamber 60 through the passage ||4 in the lower portion l2 of the plug.The operationv of the control valve 16 is the same as that of valve 16of Fig, 1, the ports ||8 being fully closed when the portion of thevalve of full diameter is placed in position over the ports. Thetapered-portionof the valve 16 provides a gradual closing of the'valve.Retracting the plungers 28 causesfuel to be supplied from the fuelsupply chamber 8.0 to the chambers above the plungers and operation ofthe plungers to force -the fuel to the engine cylinders cuts oil' thepassages ||6 and forces the fuel Apast the heck valves 60 to the enginecylinders in the ual manner. In this construction it will be noted thereare no ports provided for venting the pressure above the plungers 20 i'norder to give a sharp cut oil' of the supply of fuel to the engine-chamber 6||d which is`in communication through the port 62 with thefuel supply.

As a pumpI plunger is raised to' its uppermost the groove |42 on thepump plunger and port 00d leading to the chamber ||8d so that as theplunger attains its uppermost position the pressure above the plunger isvented through the port 84d, port |48 and port 8||d to chamber ||8d`releasing the pressure above the pump plunger and cutting olf the supplyof fuel to the engine cylinder. Duing the first portion of the movementof the plunger from its uppermost position some fuel may be supplied-tothe chamber above the plunger from the fuel supplyA chamber H8l throughthe port 80d, port |48 and port ||4d and also from the fuel chamber 60dpast the valve 16*i and 'through ports H6, |46 and 84d. Port' 60d,however, is cut ofi' very shortly aftermovement of the plunger 20lstarts and the port |,|6d is subsequently cut off and thereafter remainsf cut off, port 8|1i being reopened again upon movement-of the plunger2|)d to its lowermost,

position for the passage of fuel from the chamber-Mld. J

Inpthisgconstruction it will be noted that the fuel control valve 16ddoes not control the supply of fuel Ito the bore for the pump plungerbut controls a by-pass or waste passage which vents ha portion of thefuel from the bore for the pump plunger as thelpump plunger is operatedto force the fuel to the engine cylinder, the valve d serving to controlthis discharge from the bore for each pump plunger. In this modication,also, instead of having the pump plunger maintained at its uppermostposition while each of the other pump plungers is operated the operatingcam is so shaped that the pump plunger is returned to its lowermostposition after each operation and remains in the lowermost positionwhile each of the other pump plungers is oper^Y ated. Thus,` as eachplunger l is on its delivery or outward stroke, the remaining plungersare positioned so that the ports ||6l leading ,thereto are closed by theupper end portions of these plungers and the discharge of fuel except tothe engine cylinder corresponding to the operating plunger or past valve15d isprevented.

Inthe construction shown in Figures 19, 20 and 21 the fuel control valve15# controls the passage offuel through a waste .passage vfrom the boreof each of the pump plungers as in the modification shown in Fig. 15.The valve 15=, however, diii'ers from the valve 15d in having a groove,as at |4|IB which is\ in communication through transverse ports |50, anaxial port |52 and bore I |4 of the plug ||2 with the chamber 60 so thatthe valve controls individual ports leading to the pump bores and'not aport or passage common to all the pump sections as in the previousmodification. In this modification, as in the previous modification,fuelvis supplied through the port |20e to the chamber `||0` and ports00e to the Abores above the pump plungers 20e and the waste from thepump plunger borespasses through passages ||6e to the bore for the valve15. The pumpplungers'20e in this construction-are each provided with agroove, as at |54 and an axial vport |56 communicating through atransverse port |50 with the groove |54. The pump plunger 20e is made ofsuch a length that at its upper-Y l most position the upper end of theplunger does not cut oi -communication between the chamber above thepump plunger` and the port i|6. In the operation of this deviceretracting apump plunger 20 creates a partial vacuum above the pumpplunger which may cause some fuelto be supplied from the cham 61|e pastthe valve 15 and through the port |I to the chamber above the pumpplunger but when the pump plunger is the modification shown in Figure 15or by a suitable governor as shown in Figure Zand the plunger 20 may beoperated by a cam of any suitable contour. L

In the modication shownin'Fig. 22 a single port ||6f connects the boreof the plunger bush-- ing Ilf4 with the fuel supply and a washer |22thaving a port |60 is placed between the bushing I6t and the plug 40which holds both washer and bushing in position. The plunger 20f isgrooved as at |62 and a transverse port |64 establishes communicationbetween the groove and an axial,

port |66 which extends to the upper face of the plunger 201. With theplunger 20 positioned as shown in Fig. 22 and fuel in the chamber abovethe plunger, operation of the plunger by the cam 06 raises the plungerto close the port ||6I and force the fuel above the plunger to theengine cylinder. The discharge of fuel continues until the plungervapproaches its extreme outer position where communication is establishedfrom the chamber at the outer end of the plunger through ports |66 and|64, groove` |62 and port ||6f whereby fuel under pressure is ventedfrom the chamber to the fuel supply and the discharge to the enginecylinder is stopped; As the cam passes and the spring 20 returns theplunger to the position shown in Fig. 22, some fuel may pass fromfthefuel supply through port ||6f, groove A62 and ports.|64 and |66 to thechamber above in which the plunger is,` reciprocated. A washer, |222placed between the bushing I6s and the plugI the plunger but the port||6f is almost immediately closed by the-plunger` and a partial vacuumisA formed in the chamber above the plunger until the port I6' is againopened by the plunger 20f'whereupon fuel flows through the port II6 fromthe fuel supply,

In the modification shown in Fig. 23, a port |||l connectsthe fuelsupply to the bore of the plunger ,bushing |58 while .a port 00establishes `communication .from a fuel chamber with a groove |10 'inthe outer face oi' the bushing I6s which is connected by a port |12 withthe bore 40 and held in position by the plug is provided with a taperedrecess |14 which is open towards I the bore of the bushing |6 and with aplurality returned to its lowermost or retracted position fuel issupplied from the chamber |||le through theport 00er tothe chamber abovethe pump plunger. As the pump plunger is moved upwardly theupper/portion of the pump plunger cuts of!!` communication through theport 00 and `forces the fuel past'the check valve 50 to the enginecylinder. The groove'l54 ofy the pump plunger is sealed by thewall of`the`plunger bushing |6 until the plungerv approaches its uppermostposition when communication is established be` tween the groove |54 andthe port Ille thereby establishing communication from the chamber labove the pump4 plunger through the ports |56,

lss and la' to die chamber m, venting the pressure above the pumpplunger and cutting of! .t e'fel chamber 60, the extent of this waste orof ports |16 arranged in a circle about the recess |14. 'Ihe plunger 20has its upper orouter end tapered to enterL the tapered recess |14 andis grooved as at |10. A transverse port |00 connects the groove |10 withan-axial'port |02 which extendsl tothe outer end of the plunger. Withthe plunger 2|l`in its retracted position as shown in Fig. 23 and fuelin the chamber above the plunger operation of the plunger by a'cam 36shifts the' plunger to close the port ||6 and to force the fue) throughthe ports |16 in the plug4 |22' and past the check valve 50 to theengine cylinder until the movemeht of the plunger causes'the groove |10to register with the port |12 and open a passage for venting fuel underpressure from the chamber above the plunger v the supply of fuel tb theengine cylinder. As the Y pump plunger is moved upwardly, however, partof the fuel above the pump plunger passes `through the port III to thegroove |40* of the f v ve 15 andthrough the ports |50 and |52, to

bleed from the pump plunger bore being detery minedl bythe position ofthe valve 15. The

' valve 16 may beadiusted either manually asin through ports |02v and|00, groove |10, port |12, groove |10 and port 00H to the/ fuel chamberwhereby the discharge of fuel -to the engine cylinder is stopped.

In this modiiication, such gas or vapor as .passes to or forms in thechamber above the pump plunger 20I tends to collect in the recess 14 -inthe washer |22' and as the plunger is, raised such gas will be held inthe recess |14 while liquid fuel is forced through the ports |16. Whenthe groove l|10 is connectedvto the port |12 the gas held in the recessis thereupon vented tothe fuel chamberso that little or no gas or vaporis supplied to the discharge nozzles yby the plungers 20g. As theoperation of the cam permitsthe spring 28 to re tract'the cam some fuelmay be supplied from the fuel chamber to the chamber above 'the plungerthrough ports BU' and |12 but th'e movementof `the plunger soon closesthe port |12 whereupon a the structure shown in Fig. 7. Port H6El may becontrolled as is port lli and port 802 may be connected to the fuelsupply as is port 80". Th'e cams 36 operating the plungers of Figs. 22and 23 may be of any desired contour.

It will be noted that the above description of the structure of theinvention with reference to l the drawings begins 'with a description ofa casing structure common to many modifications and, that like orsimilar numerals refer to like parts throughout. Many`of themodifications relate to the structure of the bushings that may be alterfnatively mounted in the pump plunger bores and the pump plungers thatmay be associated therewith, and to the bushings that may be alternabeassociated therewith. The common casing structure is of simpleconstruction standardized in production for economy and various modifiedforms of bushings are removably mounted therein to receive various pumpplunger and -valve plunger structures to provide pump structures capableof differing operations as may be desired whereby'control of fuel forcedto engine cylinders may be controlled bythrottling by means of thfevalve manually oi' governor controlled, or by bleeding off by both.'While in the construction shown in Figure 3 the cam 36 has been shownas formed integral with the gear wheel 38 it need not be so as the cammay be formed as a separate member, as the cam 36l of Figure 24, whichis secured to' the gear Ill and fuel is supplied' fuel from the pumpplunger bores, or

- tively mounted in the axial bore to provide a valve chamber and thevalve plungers that may wheel 38 by a bolt |80, the cam being positionedwith respect to the gear wheel by a dowel pin |82. Figure 24 alsov showsthe pin 32IL which supports the roller 30 in` the piston plungerfollower |09 secured therein by a tapered pin |84 in place of the springwire IQ, as shown in Fig. 3.

What is claimed is:

1. A fuel injection pump for internal combustion engines comprisingasectional casing having a plurality of plunger bores uniformly spaced ina circle about an axis of said casing and a sectionalbushing in saidcasing forming a cylindri-V cal valve ch'amber disposed ,on said axiskof said casing and triangular ports at the meeting surfaces of 'saidbushing `sections connecting said valve Achamberto said bores, pumpplungers in said bores Jfor forcing fuel from said bores to thecylinders of an engine, means for operating said plungers, means forventing fuel from the plunger bores to said ports'for cutting oil' theflow of fuel from said plunger bores to the engine cylinders at a fixedpoint inthe movement of said plungers and a `cylindrical control valvein said valve chamber having a fiat end controlling said ports to governthe amount of fuel supplied to the pump plunger bores.

2. In" a fuel injection pump for. internal combustion engines. acasinghaving a plurality of plunger bores uniformly spaced in a circleabout an axis of said casing, a sectional bushing in said casing forminga cylindrical valve chamber dis; posed on said axis of said casing andhaving triangularly-shaped connections individual to said bores at themeeting surfaces of the bushing sections, pump plungers in said boresfor forcing fuel from said bores to the cylinders of an engine, meansfor operating said plungers, said plungers having ports for venting fuelfrom the plunger bores'to said valve chamber connections at fixed pointsin the movement of said plungers and an adjustable cylindrical valveplunger in said valve chamber for controlling the supply of fuel to theplunger bores individually, said valve plunger havinga fiat end arrangedto simultaneously cony trol all fuel passages.

3. A fuel injection pump for internal combus-y tion engines comprising,a casing having an axial bore and aplurality of pump plunger boresdisposed about said axial bore equidistant therefrom, a sectionalbushing in said axial bore forming a substantially cylindrical valvechamber to be connected to a fuel supply, said bushing having triangularports at the meeting surfaces of the sections thereof and said casinghaving a plurality of passages connecting each of said pump plungerbores to said valve chamber through the ports, pump plungers in saidpump plunger bores for forcing fuel therefrom to engine cylinders, meansfor operating-` said plungers, means for venting fuel from said pumpplunger bores to fuel supply for cutting olf the now of fuel from saidpump plunger bores to the engine cylinders at a 'fixedpoint in themovement of each of said plungers,` and .a fiat-ended Icylindricalcontrol valve ir said valve chamber for controlling-said ports tu governthe amount of fuel supplied to the engine cylinders by said pumpplungers.

4. In a fuel injection pump for 'internal combustion engines, thecombination comprising a casing having an axial bore and a plurality of-a'ngular-shaped portsat the meeting surfaces of the ,sections of saidbushing, pump plungers in .said 'pump plunger bores for forcing fuelfrom said pump plunger bores to engine cylinders,

means for operating said plungers, said plungers having ports for-venting fuel from the pump plunger bores to fuel supply atl fixedpoints in the movement of said plungers, and an adjustable flatfendedcylindrical valve plunger for individuallyV and simultaneouslycontrolling the supply of -fuel through the ports to said pump plungerbores.-

5.@ fuel injection pump for internal' combustion engines comprising, vincombination, a standardized casing having an axial -bore and a pluralityof pump plunger bores disposed about said atrial bore with their axessubstantially ,parallel to the axis of said axial bore, said casingbeing provided with a plurality of fuel passages associated with saidpump plunger bores to conne'ct the same to said axial bore and affordingress and egress of fuel therefor, fuel supply means including apassage in/said casing communicating with said axial bore, a pluralityof pump plungers one of which is reciprocatively mounted in each ofvsaid pump plunger bores for 4 y 4 ames v `7 forcing fuel to enginecylinders. said plunge'rs mining fuel passages are free of controlwithin aving ports' for venting fuel .from the pump thevaxial bore, anda valve movably mounted in EVER'IT M. PURDY.

